Well-being is linked with diverse and extensive networks of relationships and interests

Beginning nearly 40 years ago, social scientists began to look deeply and regularly at the ways people related to other people—spouses, family, friends, and others—and how different people were affected by their own social networks. What they discovered, and have consistently found in later studies, is that the diversity and numbers of our social connections are directly related to our health, happiness, and longevity. Social networks certainly include close friends and family members. But they extend outward from these intimate relationships to encompass extensive and often intricate networks of human ties that influence us in ways we may not even know.

"We would ask people, 'Are you married?' 'Do you belong to social groups?' 'Do you belong to a church?' 'Do you have friends?'" says Sheldon Cohen, a relationship researcher and psychologist at Carnegie Mellon University. "The more they have, the better off they are," he adds.
Cohen rattles off a list of the ways social ties influence our well-being: "It predicts mortality. It predicts cardiovascular disease. It even predicts the recovery rates from cardiovascular disease. It predicts the progress of cancer. It predicts cognitive function [in later life]. It even predicts the common cold."
Cohen's own research group has exposed healthy people to a cold virus after first measuring the state of their immune systems. About a third of the people get sick. "It turns out that their social integration scale is a really good predictor of who gets sick and who doesn't," he says.
Claude Fischer, a sociologist at the University of California at Berkeley, divides network relationships into three roles: providing emotional support, giving practical help, and social interaction, such as going to the ball park together. "Our relationships tend to be reciprocal over the long run, in terms of...